Electric-arc lamp



2 Sheets-Sheet 1.

- (No Model.)

J.B. ALLEN.

ELECTRIC ARC LAMP.

IN MI) INVENTDR: Ki (2 M n (No Model.) 2 Sheets-Sheet; 2.

J.B.ALLEN.

' ELECTRIC ARC LAMP.

No. 309,816. Patented Dec. '30, 1884.

XQQW 5? UNITED STATES PATENT OFFICE.

JOSEPH I). ALLEN, OF SPRINGFIELD, ILLINOIS.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 309,816, dated December30, 1884.

Application filed September 21,1883.

To whom it may concern:

Be it known that I, J osnrrr B. ALLEN, of Springfield, in tlie county ofSangamon and State of Illinois, have invented a certain new and usefulImprovement in Electric Arc Lights, of which the following is aspecification.

The object of this invention is to produce an electric light of thevoltaie-arc type which shall be simple and compact in its constructionand efficient in operation; and said invention consists in the noveldevices and combinations of devices employed by me in accomplishing thisobject, as hereinafter set forth and claimed.

My invention is illustrated in the accompanying drawings, in whichFigure lis aperspective view of a complete lamp embodying the preferredform of the invention; Fig. 2, an enlarged vertical section of thecylinder which incloses the regulating and cut-out devices; Fig. 3, atransverse section of the same on the line 00 a; of Fig. 2; Fig. 4, aperspective view ofa modified form of my lamp; Fig. 5, a verticalsection of the cylinder in such modilied form. Figs. 6 and 7 are detailsof mechanism for controlling the movement of the carbons, and Fi 8illustrates the use of pieces of refractory material for assisting thelight.

Referring, first, more especially to Figs. 1, 2, and 3, the lampconsists of a cylinder composed of metal sections A A G, which form acasing, anda section, B, of insulating material.

To the outside of the insulating section B 'are rigidly attached, asshown at m m, the

arms D D. Each arm D has near its outer end a hinged joint, (I, and thehinged end piece of each is attached to one of the boxes F F. Each box Fconnects two carbonholding tubes, E E or E E. Such tubes are ofsemicircular shape, and the two tubes,with the boX F, form acarbon-carrying frame. Tubes E E converge toward their lower ends, andtubes E E likewise converge, so that the curved carbons a a, carried bytubes E E, form one electrode of the lamp, and carbons bb, carried by EE, form the other electrode. The position of frames E and E isadjustable at d d, so that the proper position for the are can beattained; but before the lamp is put in operation frame E is fixed bytightening the screw at the hinge so that the regulation of the (X0model.)

are is accomplished by the movement of one electrode alone. Thesemicircular carbons a a b b may be of any suitable section, fiat,halfcylindrical, or square, and those of each pair forming one electrodeconverge at an acute angle touching at their ends. Apoint of consumptionis thus formed for the electrode which remains constant, beingdetermined by the geometrical intersection of two fixed lines and not byany regulating mechanism. If the carbons are not burning,each pair isprevented from moving forward by the contact at the points; but when thelamp is in operation they will move forward just as fast as they areconsumed, and the points will always be in contact. The tubes EE, whichare movable in the operation of the lamp, are connected near their upperends by a crosspiece, e. To the middle of this cross-piece a long screw,M, is attached by a link-j oint, f. Upon this screw llI is screwed themovable soft-iron core L of a magnet or solenoid, S, supportedhorizontally in the upper part of the cylinder and having its coilsincluded in the main circuit. Screw M terminates in a round head, g,from which a spring, h, extends and is connected with screw M, whichpasses through a piece, 70, in the side of the casing and has a milledhead, i. Spring h opposes the attraction of magnet S, and its tension isadjusted by screw M. Core L is adjustable upon screw M, and the amountof play of such core in and out of S can thus be adjusted for thedifferent currents with which the lamp may be used. These parts form thewhole of the regulating apparatus in this form of lamp, and theiroperation is as follows: The electrodes being together when currentpasses to the lamp, magnet S draws core L and screw M toward it, andthus moving the pivoted frame E E separates the electrodes at theirlower ends and starts the arc. If the arc becomes too long the magnetweakens, and spring h causes the frame to move in the opposite directionand bring the electrodes to their proper position again.

, The cutout mechanism shown in Figs. 1, 2, and 3 is, in general,similar to that set forth in my Patent No. 275,345. In the present case,however, instead of simply closing circuit around the lamp, I closecircuit through a resistance equal to that of the lamp, and I provide anadjustable resistance, so that it can be altered for use under differentconditions.

The circuits through the lamp are as follows: From binding-post X twowires, Z and Z, extend. lVire Z includes the coils of magnet S, andthence extends to the metal piece m Thus connection is made through armD and tubes 1 1E to electrode a a. From binding post X wire Z extendsdirect to m, and is thus connected with electrode Z) Z). Thebindingposts are inserted in the piece of insulating material 13, whichcloses the cylinder at the top. The high-resistance magnet or solenoidT, which operates the cut-out, is supported from B by piece it. Itscoils are in the finewire shunt 0, extending from m and 022. Below it isplaced the soft-iron armature p, supported at the end of rod q, and fromthe other end of q the vertical rod r extends to above the magnet, andprojecting from it is the catch 8, whose edge enters a notch, Z, nearthe top of the movable core U of magnet T. To the lower end of U issecured the metal piece, Vshaped, as a part of a cone. A, flat spring,a, secured to r, presses against piece 12, secured to the side of themagnet.

\Vithin the insulating-section B on one side is secured the curved metalblock w, beveled on the upper edge of its inner side. The lower end of Bis closed by the insulating-disk B and this supports the metal piece 20,which also is of curved form and beveled at its top.

Upon the lower side of disk B is secured a metal plate, From this plateextend downwardly a number of carbon rods, 0 c, of dil i'erent lengths.An insulating-cylindcr, d, extends down from disk 11-, and upon it fitsa cup, 0, of insulating material containing mercury f. Long screws 1/ 9,which attach piece m to piece 13*, extend through apertures in plate iswithout touching the plate, and dip into the mercury. A hollow tube, It,of insulating material is in the center of cup 0, and through the bottomof the cup, through tube 71, and through disk B" extends the screw '1',having nuts 7.1. By turning screw 1? the cup 6 is moved up or down, sothat more or less of the carbon pencils dip into the mercury. The wireZi'rom binding-post X is connected at the upper end of screw t. Theparts being in the position shown, if the carbons break or currentthrough them ceases from any other cause, current will pass through thehigh resistance shunt o 0, the magnet T will be energized, and themagnetism of core U will attract armature p forward, so that the catch.9 will be withdrawn from the notch and the core U will drop, its weightbeing too great to be upheld by the magnet. The piece \V then bridgesthe contacts 20 and w, and circuit is closed from binding-post K,through wire Z, screw t", plate 2, carbon pencils 0, mercury f screws g,contact-piece w, cut-out V, contact w, and wire Z to binding-post X. Acircuit of equal resistance to the lamp is thus closed around the are,and this resistance is adj ust-able by varying the number of carbon rodsin contact with the mercury.

When the lamp is not in use, it may be cut out of circuit by pulling thecord 12,, and thus withdrawing catch 8 and allowing U and V to fall, andit is replaced in circuit by pulling cord of, which raises U and 'V anddrops armature p.

The modified form of regulator shown in Figs. 4 and 5 allows a verydelicate adjust ment of the distance between the electrodes, permittinga wide range of movement of the core of the control]ing-magnet forproducing very slight changes in the distance between the electrodes.

The main-circuit magnet or solenoid S is placed vertically in thecylinder, being supported from the insulating-disk B", and its movablecore L projects below the cylinder. In this case the core is solid, andis placed upon the end ol'screw M, which passes through the block N, andby turning the screw the position of the core relative to the magnet isadjusted. From block X the two arms K K extend, each having aninterposed section, 1 of insulating material. At the ends of these arms,respectively, are carried the grooved wheels I I, which run on rods G G,which rods are hinged at their lower ends to the'main arms 1) D of thelamp, which in this case are hinged at their inner ends, and are curveddownwardly and connected with the boxes F F of the carboncarrying framesby arms 1) D, which in tact i'orm parts of the main arms. Screws H andll pass through arms I) D and rods G (3, by turning which theinclination ot' the latter is changed. A third arm, N, extends fromblock N at right angles to K 11, and carries at its end a rod, 0, whichextends up through guide 0, supported from insulating -section 13, theupper portion of which rod is scrcw-tlnreaded, and has upon it the twonuts l and 1?. A metal strip, )1, extends from guide 0 to plate fromwhich arm I) extends. A bindingpost, Q, projects from theinsulating-section and carries two small metal strips or rods, extendingup beneath the 'nut 1". 'Within the cylinder from binding-post (Q wire 0extends to theJtigh-resistance helix T of the cut-out. .l.he otherconnection, 0, of helix T is to m. 1y adjusting the nuts upon screw 0the extent of movement of core L is determined.

The cut out mechanism is substantially like that previously described;but it is placed in the upper part of the cylinder, and instead ofmercury-cup 0 being adjustable, the plate Z, which carries thecarbon-resistance rods 0 c, is movable relative to the cup by turningscrew 1" through the bevelgears s s, by means of spindle 1, whose head ais without the case. Further, the cord a, by which core U is raised, inthis case extends over a pulley, c, at the top of the cylinder, as in mypatent above re ferred to.

The operation of these regulating and out ICC out devices is as followsCircuit being closed to the lamp, when the electrodes are together, thedrawing up of core L moves the grooved rollers I I up the rods G G andforces the arms D D out, thus forming the arc, and the arc is thenregulated by the movement of the rollers on the rods, caused by changesin strength of magnet S. If the arc-circuit is interrupted in any way,core L falls, and with it rod 0, and nut P strikes q, closing circuitthrough 0, p, Q, and 0 to solenoid T, when the cut-out acts to throw thecarbon-resistance rods into circuit, as previously explained.

A mode of combining the two forms of regulating apparatus above setforth is illustrated by the dotted lines in Fig. 4. The magnet S isplaced horizontally, and core L and screw M are arranged as in Figs. 1.and 2. The ear bon carrying frames are then hinged upon arms D D, asinFigs. 1 and 2, and said arms are not themselves hinged, as in Figs.-.land 5. The cut-out devices are placed in the lower end of thecylinder, below the horizontal magnet, precisely as seen in Figs. 2 andS.

Devices for assisting the feeding forward of the carbons in the tubesare illustrated in Figs. 6 and 7. In the form shown in Fig. 6 thecarbons are inclosed in separate rack-tubes a a which pass through theboxes F. On one side of each tube the two grooved rollers b If bear,while between the tubes are the two cog-wheels 0* c driven by the springdiwhich assists the force of gravity to drive the carbons down as theyare consumed. \Vhen new carbons are put in, the racks are pushed upagain, and the spring is thus wound up. The pressure of rollers b isadjusted by set-screw e and spring f.

In Fig. 7, instead of the cog-wheels and racks, wheels 9* 5 havingrubber tires which bear directly upon the carbons themselves, are used.

To further increase the steadiness and uniformity of the light, as wellas to render it softer and less trying to the eye, I place a triangularpiece of high]y-refractory insulating material, h, Fig. 8, between thecarbons of each electrode. It is supported adjustably from cross-pieceby screw it, and fits the angle closely. Besides, by its ineandescence,rendering the light steadier and brighter, this re fraetory piece keepsthe air from the inner surfaces of the carbons, and thereby preventsthem from being consumed back of the point of contact, thereby keepingthe angle of intersection of the inner surfaces fixed, and preventingany change in the distance between the carbons. I employ, also, a thirdrefractory piece, m placed on top of the two electrodes and supportedfrom the cylinder. The bottom of this piece is curved to fit the curvedcarbons, and the are plays along it, so that it becomes heated toineandescence, and thus makes the light more brilliant, steadier, andsofter.

The carbons which I use I prefer to make in the following manner: I cutpaperorcloth, or other suitable carbonizable material, into pieces ofthe proper curved shape, soak these in a tarry or resinous material andpack them in a mold, sifting over each a small quantity of coke-dust,and pressing them all tightly together, and then carbonize. This form ofcarbon disintegrates rapidly, and thus more in candescent particles arethrown into the are, and it is made more luminous.

It is evident that more than two carbons all converging at acute angles,may be used for each electrode, and may be arranged and regulated in themanner described.

\Vhat I claim is- 1. In an electric-arc lamp, an electrode consisting oftwo or more curved carbons situated side by side and meeting at an acuteangle or angles, substantially as set forth.

2. The electrodes of an electricarc lamp, each consisting of two or morecurved carbons situated side by side and meeting at an acute angle orangles, substantially as set forth.

In an electric-arc lamp, the combination of two curved pivoted framescarrying the electrodes, an elcctro-magnet or solenoid having its coilsin the main circuit, its movable core or armature, and suitablemechanical connections from said core or armature to said frames,substantially as set forth.

4-. In an electric-arclamp, the combination, with asupporting-body,oftwo pivoted frames, each consisting of two curved tubes convergingtoward their lower ends, and each tube holding a curved carbon,substantially as set forth.

In an electric-arc lamp, the cylinder inclosing the regulating mechanismand supporting the clectrode-carriers, having an insulating section towhich such carriers are at tached, substantially as set forth.

6. In an electric-arc lamp, the combination of the central cylinderhaving an insulatingscction, the pivoted curved carbon-holding framesattached to opposite sides of said insulating-section, the regulatingmagnet or solenoid within said cylinder, its movable core, and suitablemechanical connections from said core to said carbon-holders,substantially as set forth.

7. In an electric-arc lamp, the combination, with the converging carbonsof a compound electrode, of a triangular piece of refractory insulatingmaterial situated in the angle at the mecting-point of said carbons,substantially as set forth.

8. In an electric-arc lamp, the combination, with curved electrodesmeeting at their ends,

of a similarly-curved piece of refractory insulating material in contactwith their ends above the are, substantially as set forth.

9. In an electric-arc lamp, the combination, with curved electrodesmeeting at their ends, each composed of two curved carbons converging atan acute angle, of triangular pieces of refractory insulating materialin the angle or angles of each electrode, and a curved piece ofrefractory material in contact with the ends of the electrodes above theare, substantially as set forth.

10. The combination, with an electric-arc lamp, of an adjustableresistance in a shunt 1' around the arc, and means actuated by thecessation of current in the arc-circuit i'or closing circuit throughsaid adjustable resistance, substantially as set forth.

11. The combination, with an electricarc lamp, of a mercury-cup and anumber of resistancerods in ashnnt around the are, means for placingmore or less of said resistance-rods in contact with the mercury, andmeans aetuated by the cessation of current in the arccircuit for closingsaid shunt-circuit, substanl tially as set forth.

l l 12. The combination of the insulating-disk Joan E. BRCHVN,

supported in the cylinder, the plate attached beneath the same andcarrying the resistance I rods, the mercury-cup, and the screw formoving said cup up and down, substantially as set forth.

13. The combination of the cut-out magnet or solenoid in a shunt aroundthe arc, the movable core thereof, the catch supporting said core, andadapted to be withdrawn by the attraction of said magnet or solenoid,the contacts bridged by said core when it falls, the plate carrying theresistance-rods, the mercury-cup, and connections from the mercury, andthe resistance-rods through such bridged contacts, forming a shuntaround the arc, substantially as set forth.

In testimony whereof I have hereunto subscribed my name this 1st day ofSeptember, 1888.

l s l l i JOSEPH l3. ALLEQ. 'Witnesses:

SAM ll. Gummy.

